Re: [RFC net-next 07/18] tun: set offloaded xdp program

From: Prashant Bhole <prashantbhole.linux@gmail.com>
To: Jason Wang <jasowang@redhat.com>, David Ahern <dsahern@gmail.com>,
	"David S . Miller" <davem@davemloft.net>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	John Fastabend <john.fastabend@gmail.com>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
	netdev@vger.kernel.org, qemu-devel@nongnu.org,
	kvm@vger.kernel.org
Subject: Re: [RFC net-next 07/18] tun: set offloaded xdp program
Date: Mon, 9 Dec 2019 09:24:34 +0900	[thread overview]
Message-ID: <ba0c0d5f-fbb4-ff92-c7d8-403dbb757758@gmail.com> (raw)
In-Reply-To: <8d575940-ba31-8780-ae4d-6edbe1b2b15a@redhat.com>

On 12/2/19 11:47 AM, Jason Wang wrote:
> 
> On 2019/12/2 上午12:45, David Ahern wrote:
>> On 11/26/19 4:07 AM, Prashant Bhole wrote:
>>> From: Jason Wang <jasowang@redhat.com>
>>>
>>> This patch introduces an ioctl way to set an offloaded XDP program
>>> to tun driver. This ioctl will be used by qemu to offload XDP program
>>> from virtio_net in the guest.
>>>
>> Seems like you need to set / reset the SOCK_XDP flag on tfile->sk since
>> this is an XDP program.
>>
>> Also, why not add this program using netlink instead of ioctl? e.g., as
>> part of a generic XDP in the egress path like I am looking into for the
>> host side.
> 
> 
> Maybe both, otherwise, qemu may need netlink as a dependency.
> 
> Thanks
> 

Thank you all for reviewing. We will continue to improve this set.

If we split this work, Tx path XDP is one of the necessary part
which can be developed first. As suggested by David Ahern it will be
a netlink way but we will still need ioctl way for tap. I will try
to come up with Tx path XDP set next time.

Thanks.